Modular flange

ABSTRACT

A multipart gas pipe flange for connecting to a counter-flange of an internal combustion engine, having at least one flange plate designed as an outer flange, and having a flange inner part that can be received in said flange plate and is used for attaching a gas pipe which is connected downstream of the inner part in the flow direction and which is fluidically connected. The flange plate has at least one recess for the flange inner part, said recess having at least one inner surface and an inner diameter Di, and a mounting surface which can be placed at least indirectly on the counter-flange. The flange inner part has an outer surface which corresponds to the inner surface and which has an outer diameter Da. The outer surface and the inner surface have a basic shape which tapers in the flow direction, and when being clamped against the counter flange, the outer surface and the inner surface can be clamped relative to each other at least partially in a direction (R) which runs radially in relation to a central axis of the outer surface and/or the inner surface.

FIELD OF THE INVENTION

The invention relates to a multipart gas, exhaust, or mixed pipe flange for connecting to a counter-flange such as a cylinder head flange or an exhaust gas turbocharger flange of an internal combustion engine, comprising at least one flange plate forming an outer flange, having at least one recess for a flange inner part, having a central axis and an inner diameter, and comprising a flange inner part for attachment of a gas pipe connected downstream and in fluidic connection, such as an exhaust gas manifold pipe or a fresh air line, which is mounted inside the recess, wherein the flange inner part has an outer surface corresponding to the recess with an outer diameter Da. In particular, the counter flange will be the cylinder head or the exhaust gas turbocharger or other pipe flanges on the exhaust gas and/or fresh air side of an internal combustion engine, such as a catalytic converter.

BACKGROUND OF THE INVENTION

A flange ring of an internal combustion engine is already known from DE 196 42 692 C2, having a recess for an exhaust gas pipe and comprising a reinforcement ring which is mounted indirectly across the exhaust gas pipe in the recess, wherein an exhaust gas inner pipe is provided, formed from a material which is more temperature resistant than the exhaust gas pipe, and wherein the reinforcement ring and the exhaust gas pipe have an outer surface configured as part of a sphere, corresponding to the inner surface of the flange ring, while the outer surfaces and the inner surface when joined to the cylinder head of the internal combustion engine can be clamped relative to each other.

An exhaust gas manifold flange is known from DE 10 2006 020 608 B4, being formed from a flange and a flange ring guided therein. The flange ring is configured conically according to sample embodiment FIG. 5 and lies by a collar against a sealing element on the cylinder head.

DE 102 20 986 B4 describes an exhaust gas manifold flange with at least one flange plate, which can be mounted on a cylinder head, while the flange plate has at least one recess for a flange inner part, and with a flange inner part which is guided through the recess and serves to secure an exhaust gas pipe. The flange inner part is made from material more temperature resistant than the flange plate and is connected to the flange plate by means of IHU methods or by press fitting and/or welding. It has a conically configured bearing surface, by which it can be brought to bear directly against a cylinder head outlet.

A manifold arrangement consisting of several pipe bundles is known from DE 1 164 157 B. The individual chambers of the line are connected by sockets to the cylinder outlets and this by a sliding flange, which enables a lengthwise expansion of the line relative to the cylinder blocks. The sliding flange is formed from the socket, which is secured on the cylinder via a locking and clamping rail. At the top the sockets and rails are step shaped, and at the bottom they have a bevel or facet.

Accordingly, it is assumed that the locking and clamping rail is formed from two partial rails, similar to that known from EP 1 571 305 A1. The sliding flange is meant to ensure a lengthwise expansion (at right angles to the plane of the drawing). It is therefore to be assumed that the locking and clamping rail extends only in the lengthwise direction, i.e., at right angles to the plane of the drawing, so that it can likewise be inferred that it is formed from two partial rails.

SUMMARY OF THE INVENTION

The problem of the invention is to configure and arrange the gas pipe flange such that a simplified construction and a more favorable fabrication of the gas pipe flange are assured.

The problem is solved according to the invention in that the flange inner part has an outer surface configured conically in terms of basic shape which tapers in the flow direction and the flange plate has an inner surface configured conically in terms of basic shape which tapers in the flow direction, wherein the outer surface and the inner surface when the gas pipe flange is being clamped against the counter flange can be clamped relative to each other in a direction R which runs radially in relation to the central axis. The clamping is done preferably about the circumference, either uniformly or also only in certain sections, by use of the recesses described hereafter. This results in a form fit acting in the radial direction as well as the axial direction to the center axis between the flange inner part and the flange plate. This ensures that the flange plate and the flange inner part are pressed together solely by tightening against the counter flange with the aid of the mounting bolts with a force component acting in the radial direction and in axial direction to the center axis. No additional joining processes are needed for connection of flange plate and flange inner part, such as soldering, welding or joining The outer surface and the inner surface, depending on the surface texture and the type of surface, can also bear against each other only by segments and/or points.

Furthermore, it can be advantageous to make the flange inner part from material which is more temperature resistant than the flange plate at the exhaust gas side when used for an exhaust gas manifold for a cylinder head or an exhaust gas turbocharger. The use of such a mix of materials can save on costs, because the flange plate can be made from lower alloy steel.

For this, it can also be advantageous for the outer surface and the corresponding inner surface to be configured as a conical envelope surface in regard to basic shape and to have an axial overlap d of at least 2 mm to 5 mm in regard to the center axis. The axial overlap d corresponds to the thickness of the flange plate or the flange inner part, when these are flat in configuration. With increasing overlap d, the possible surface pressure between the outer surface and the inner surface becomes less. The flange plate or the flange inner part are at least 2 mm thick in this case.

In the context of the configuration and arrangement according to the invention, it can be advantageous for the outer surface and/or the inner surface to be profiled and/or to have grooves, recesses or slots running in the circumferential direction and/or in the radial direction and/or in the axial direction with respect to the center axis. Accordingly, it is also possible to have the outer surface and/or the inner surface profiled, such as with grooves running in the circumferential direction, so that the surface pressure is increased, and thus the tightness improved, despite the existing overlap d.

Moreover, it can be advantageous for the flange inner part and/or the flange plate to be formed from deep drawn and/or punched out sheet metal. The process safety achieved in this way is even further enhanced by the conically configured contact surfaces between the flange inner part and the flange plate, because a sufficiently large pretensioning can be realized even with relative large tolerances in regard to its configuration.

It can be advantageous for the flange inner part to have a bearing surface for a seal, such as a flat seal, by which the seal can be tensioned against the counter flange. With the help of the seal, defined bearing conditions can be easily accomplished between the two-part gas pipe flange and the counter flange, so that only the flange inner part bears in sealing manner against the counter flange. If the flange inner part sticks out in the axial direction beyond the mounting surface of the flange plate, it can be advantageous for the seal to reach into the zone of the mounting bolts for the gas pipe flange, so that a simple placement and preliminary fixation is possible.

Alternatively or additionally it can be advantageous for the flange inner part at least in the assembled condition to stick out in the axial direction beyond the mounting surface of the flange plate. In this way, a defined bearing of the flange inner part against the counter flange or a seal inserted in between is assured. The mounting surface of the flange plate thus is not tensioned against the counter flange, as this would affect the bearing conditions of the flange inner part. The press fit between the flange plate and the flange inner part is preserved in this way.

Furthermore, it can be advantageous for the flange plate to be formed from several plates, each with a recess, while the respective recess is conical or cylindrical in configuration and all the recesses form the conical basic shape of the inner surface. In the case of the cylindrical recess, these differ in diameter so that on the whole a conical inner surface is still produced at least in terms of basic shape, albeit of stepped form, which clamps the flange inner part across its outer surface.

It can also be advantageous to provide a gas pipe such as an exhaust manifold pipe or a manifold that is fastened solely on the flange inner part and stands in fluidic connection with the flange inner part. In such a system, the flange inner part and the gas pipe or the manifold pipe provide for the relaying function on account of the gas-tight connection. The flange inner part has a central outlet hole, to which the gas pipe or the manifold pipe is connected.

It can be advantageous to provide a seal having an encircling sealing bead that bears or at least can bear against a bearing surface of the flange inner part and/or against the counter flange, wherein the sealing bead in the area of the flange inner part at least in the assembled condition sticks out in the axial direction beyond the mounting surface of the flange plate. In this way, the bearing conditions defined by the flat seal with bead are also determined in regard to the press fit.

Also advantageous is a method for making a gas pipe flange in which at least the recess of the flange plate or the flange plate and/or at least the outer surface of the flange inner part or the flange inner part are made by means of a deep drawing process and/or a punching process. Deep drawing processes and/or punching processes have a high degree of production safety and are also economical for this reason.

BRIEF DESCRIPTION OF THE DRAWINGS

Further benefits and features of the invention are discussed in the patent claims and in the specification and represented in the figures. There are shown:

FIG. 1, a sectional representation of an exhaust gas manifold flange with cylinder head;

FIG. 2, view A-A of FIG. 1;

FIG. 3 a-3 c, further embodiments.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 involves an exhaust gas manifold flange 1 for a cylinder head 2. The exhaust gas manifold flange 1 shown in FIG. 1 is connected to an outlet 2.1 of a cylinder head 2 of an internal combustion engine. It is multi-part and has a flange plate 1.1, which has a recess 3 for a flange inner part 1.2. The flange inner part 1.2 is installed or mounted inside the recess 3, which has a center axis 3.1. The flange inner part 1.2 stands in fluidic connection with an outlet 2.1 of the cylinder head 2 and has an outlet hole 3.2, which is arranged coaxial to the outlet 2.1. In order to accommodate the flange inner part 1.2, the latter has a conically configured outer surface 4 in terms of basic shape that tapers in the direction of the center axis 3.1 and the flange plate 1.1 has a corresponding inner surface 5, likewise conical in basic shape and bearing against the outer surface 4, wherein the outer surface 4 and the inner surface 5 when clamped against the cylinder head 2 of the internal combustion engine can be clamped together in the direction of a surface normal N and thus in a direction R running radially to the center axis 3.1. The clamping against the cylinder head 2 of the internal combustion engine occurs via a recess 1.4 for mounting bolts (not shown) on the cylinder head 2.

The conically configured outer surface 4 and the inner surface 5 taper in the flow direction S. Both of them are in the configuration of an envelope surface of a cone and have an axial overlap d at the thickness of the flange plate 1.1 of around 5 mm in relation to the center axis 3.1.

FIG. 1 shows two sample embodiments, separated by the center axis 3.1.

According to this representation, at the left side of the figure the outer surface 4 of the flange inner part 1.2 has slots or grooves 4.1 running in the circumferential direction, which heightens the surface pressure between the inner surface 5 and the outer surface 4. The slots or grooves 4.1 can alternatively or additionally be provided, as shown at the right side of the figure, in the inner surface 5. The slots or grooves 4.1 can also be arranged (not shown) running in the axial or radial direction in relation to the center axis 3.1.

The flange inner part 1.2 has a bearing surface 1.3, against which a seal 6 bears. The seal 6 can thus be clamped via the flange inner part 1.2 and the mounting bolts (not shown) against the cylinder head 2. The seal 6 has an encircling sealing bead 6.1, which in the sample embodiment on the left side of the figure can bear at least against the cylinder head 2. According to the sample embodiment on the right side of the figure, the sealing bead 6.1 bears against the bearing surface 1.3 of the flange inner part 1.2. The sealing bead 6.1 can also be provided on both sides of the flat seal 6, so that this can bear against both the cylinder head 2 and the bearing surface 1.3. Thus, it is ensured that the flange inner part 1.2 bears tightly or is pretensioned indirectly via the sealing bead 6.1 against the cylinder head 2 and the flange plate 1.1 does not hinder this tight abutment. Furthermore, the seal 6 according to the right side of the figure has a recess 6.2, by which it can be placed on the mounting bolts (not shown).

The flange inner part 1.2 sticks out by its bearing surface 1.3 in the axial direction beyond a mounting surface 1.5 of the flange plate 1.1 by the dimension a, so that additionally or alternatively to the above-described action of the sealing bead 6.1 a sufficient abutment or pretensioning of the flange inner part 1.2 against the cylinder head 2 is assured. An excessive pretensioning of the flange plate 1.1 or a bearing of the latter against the cylinder, which might influence the tight abutment of the flange inner part 1.2, is thus avoided.

Thanks to the two-part design of the gas pipe flange 1, the flange inner part 1.2 can be made from material more temperature resistant than the flange plate 1.1.

A manifold 7 is arranged or secured gas-tight inside or at the recess 3 of the flange inner part 1.2.

According to the sectional view A-A of FIG. 2, four recesses 1.4 are provided inside the flange plate 1.1 for the mounting bolts (not shown). The flange plate 1.1 can be provided separately for each cylinder or also as a collective plate for several cylinders.

According to the embodiment of FIG. 3 a, the flange plate 1.1 is multi-part, formed from four sheet metal plates 1 a, 1 b, 1 c, 1 d. The respective plate 1 a, 1 b, 1 c, 1 d has a cylindrical recess 3 a, 3 b, 3 c, 3 d which are reduced in diameter in relation to the flow direction S. Thus, on the whole, one gets a stepwise conical inner surface 5. The flange inner part 1.2 here is substantially thicker in configuration.

According to embodiment FIG. 3 a, the flange inner part 1.2 is thin-wall, preferably made from sheet metal, while the outer surface 4 and the flange inner part 1.2 are made by a deep drawing process and/or a punching process.

According to embodiment FIG. 3 c, the flange plate 1.1 and the flange inner part 1.2 are thin-wall, preferably made from sheet metal, while the inner surface 5 and the flange plate 1.1 are also made by a deep drawing process and/or a punching process.

LIST OF REFERENCE SYMBOLS

-   1 Gas pipe flange, exhaust or mixed manifold flange -   1.1 Flange plate, outer flange -   1 a Plate -   1 b Plate -   1 c Plate -   1 d Plate -   1.2 Flange inner part -   1.3 Bearing surface -   1.4 Recess of 1.1 -   1.5 Mounting surface -   2 Counter flange, cylinder head, cylinder head flange -   2.1 Outlet -   3 Recess -   3 a Recess -   3 b Recess -   3 c Recess -   3 d Recess -   3.1 Center axis -   3.2 Outlet hole -   4 Outer surface, contact surface -   4.1 Groove, slot -   5 Inner surface, contact surface -   6 Seal, O-ring -   6.1 Sealing bead -   6.2 Recess of 6 -   7 Gas pipe, manifold, exhaust manifold pipe, manifold pipe -   a Projection, dimension -   d Overlap -   Da Outer diameter of 4 -   Di Inner diameter of 5 -   N Normal to the surface -   R Direction -   S Flow direction 

What is claimed is:
 1. A multipart gas pipe flange for connecting to a counter-flange of an internal combustion engine, comprising: at least one flange plate designed as an outer flange, and comprising a flange inner part that can be received in said flange plate and is used for attaching a gas pipe which is connected downstream of the inner part in a flow direction and which is fluidically connected, wherein the flange plate has at least one recess for a single flange inner part, having an inner surface and an inner diameter Di, and a mounting surface which can be placed at least indirectly on the counter-flange, wherein the flange inner part has an outer surface which corresponds to the inner surface and which has an outer diameter Da, wherein the outer surface and the inner surface have a basic shape which tapers in the flow direction, and when being clamped against the counter flange the outer surface and the inner surface can be clamped relative to each other at least partially in a direction R which runs radially in relation to a central axis of the outer surface and/or the inner surface.
 2. The gas pipe flange according to claim 1, wherein the outer surface and the corresponding inner surface are formed as an envelope surface of a cone in basic shape and have an axial overlap d of at least 2 mm to 5 mm in regard to the center axis.
 3. The gas pipe flange according to claim 2, wherein the outer surface and/or the inner surface are profiled and/or have grooves, recesses or slots running in a circumferential direction and/or in a radial direction and/or in an axial direction in relation to the center axis.
 4. The gas pipe flange according to claim 1, wherein the flange inner part and/or the flange plate are made from deep drawn and/or punched sheet metal.
 5. The gas pipe flange according to claim 1, wherein the flange inner part at least in the assembled condition sticks out in an axial direction beyond the mounting surface of the flange plate.
 6. The gas pipe flange according to claim 2, wherein the flange plate is formed from several plates each with a recess, while the respective recess is conical or cylindrical in configuration and all the recesses form the conical basic shape of the inner surface.
 7. The gas pipe flange according to claim 1, wherein the flange inner part is formed from material more temperature resistant than the flange plate.
 8. A system consisting of a gas pipe flange according to claim 1, wherein a gas pipe is provided that is fastened only on the flange inner part and stands in fluidic connection with the flange inner part.
 9. A system consisting of a gas pipe flange according to claim 1, wherein a seal is provided, which has an encircling sealing bead which can bear against a bearing surface of the flange inner part and/or against the counter flange, wherein the seal has a sealing bead in the area of the flange inner part that at least in the assembled condition sticks out in an axial direction beyond a mounting surface of the flange plate.
 10. A system according to claim 7 mounted on an exhaust gas system and/or on an internal combustion engine.
 11. A method for making a gas pipe flange according to claim 1, wherein at least the recess of the flange plate and/or at least the outer surface of the flange inner part are made by a deep drawing process and/or a punching process.
 12. The gas pipe flange according to claim 3, wherein the flange inner part and/or the flange plate are made from deep drawn and/or punched sheet metal.
 13. The gas pipe flange according to claim 12, wherein the flange inner part at least in the assembled condition sticks out in the axial direction beyond the mounting surface of the flange plate.
 14. The gas pipe flange according to claim 13, wherein the flange plate is formed from several plates each with a recess, while the respective recess is conical or cylindrical in configuration and all the recesses form the conical basic shape of the inner surface.
 15. A system consisting of a gas pipe flange according to claim 14, wherein a gas pipe is provided that is fastened only on the flange inner part and stands in fluidic connection with the flange inner part.
 16. The system according to claim 15, wherein a seal is provided, which has an encircling sealing bead which can bear against a bearing surface of the flange inner part and/or against the counter flange, wherein the seal has a sealing bead in the area of the flange inner part that at least in the assembled condition sticks out in the axial direction beyond a mounting surface of the flange plate.
 17. A method for making a gas pipe flange according to claim 7, wherein at least the recess of the flange plate and/or at least the outer surface of the flange inner part are made by a deep drawing process and/or a punching process. 